A pro-Russian separatist stands at the crash site of Malaysia Airlines flight MH17 before a visit by Organisation for Security and Cooperation in Europe (OSCE) monitors, near the settlement of Grabovo in the Donetsk region on July 18, 2014. -- PHOTO: REUTERS

WASHINGTON (AFP) - US President Barack Obama spoke by phone on Friday with the leaders of Germany, Britain and Australia to discuss how to respond to the downing of a Malaysian jetliner in eastern Ukraine.

The calls to Chancellor Angela Merkel and prime ministers David Cameron and Tony Abbott came after Obama said the missile that Washington believes brought down the passenger plane came from rebel-held territory in eastern Ukraine.

The calls to the three leaders all covered the disaster that befell flight MH 17, deputy national security advisor Ben Rhodes said.

In the call with Abbott, Obama offered condolences for the loss of Australians on board the jet, which was travelling between Amsterdam and Kuala Lumpur when it went down on Thursday.

"The two leaders discussed the importance of a prompt, full, unimpeded and transparent international investigation, and they stressed the need for immediate access by international investigators to the crash site," said a White House statement.

Obama earlier said that the apparent shooting down of the plane was a "wake up call", for Europe particularly, over the danger of the deepening crisis in Ukraine and the need to toughen sanctions against Russia, which Washington accuses of destabilising the country.

Obama delivered a similar message in the calls to Cameron and Merkel.

Vice-President Joe Biden was also working the phones to talk about the aftermath of the shooting down of the Malaysia jet, which killed all 298 people on board.

He spoke for the second day running with Ukrainian President Petro Poroshenko and Polish Prime Minister Donald Tusk.

Tusk and Biden noted that Russia was "supplying weapons and training - including anti-aircraft weapons - to the separatists, with profoundly de-stablilising consequences", a White House statement said.